Pusher incident: Increased latency - US2 cluster

Affected components

• Channels WebSocket client API
• Channels presence channels

1. postmortemOct 23, 2025, 14:16 UTC

   ## **Root Cause Analysis: Increased Latency and Message Delivery Failures – US2 Cluster** **Incident Date:** October 19, 2025 **Duration:** 00:44 UTC – 08:17 UTC **Status:** Resolved ### **Summary** On October 19, 2025, customers using Pusher experienced increased latency and message delivery failures. These issues primarily affected the US2 cluster, with intermittent impact also observed in the MT1 and US3 clusters.  The incident resulted in delayed or undelivered messages for many applications. Latency stabilized at 08:17 UTC after mitigation actions were completed. ### **Impact** Between 00:44 UTC and 08:17 UTC, multiple customers experienced: * **Delayed or failed message delivery** across affected clusters * **Degraded performance** in connection establishment and publishing The most significant and prolonged impact occurred in the **US2 cluster**, while **MT1** and **US3** clusters saw elevated latency for a shorter period before stabilizing. ### **Root Cause** The pr

2. resolvedOct 19, 2025, 08:17 UTC

   Latency has remained stable over the past three hours. Our investigation identified multiple contributing factors to the earlier latency increase, including network saturation and capacity limits at our cloud providers affecting the US2 cluster. The US3 cluster issue was resolved quickly through autoscaling, while the US2 cluster experienced scaling delays that required manual intervention. We are implementing corrective measures to prevent recurrence and improve system resilience.

3. identifiedOct 19, 2025, 04:03 UTC

   We have scaled all three clusters out to handle the increased traffic. We anticipate the latency to slowly improve.

4. identifiedOct 19, 2025, 03:11 UTC

   The issue has been identified and we are applying mitigations. We are seeing improved latency in main and us3 clusters. us2 still has elevated latency.

5. investigatingOct 19, 2025, 00:44 UTC

   Increased latency and degraded performance on clusters main, us2 and us3.

What APIStatus.watch saw

Our 5-minute checks didn't record a change in Pusher's overall status around this incident. Smaller or regional incidents often leave a provider's overall status green.

How often does Pusher have incidents?

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